Research is being conducted to explore certain factors related to the role of dental materials in caries prevention. The research is divided into two phases. One phase is concerned with the feasibility of imparting anticariogenic properties to four pit and fissure sealants via the addition of various quantities of sodium and stannous fluoride. The availability of the fluoride in the various formulations is being studied and also the effect of the additions on pertinent physical properties. The formulations are screened for fluoride availability by determining the amount of fluoride leached from discs of material when immersed in water. Promising formulations then will be assessed on the basis of the change induced in the solubility and fluoride content of intact enamel surfaces. The second phase of the study deals with a basic investigation of the wettability of tooth structure and restorative materials. Wettability is assessed by contact angle measurements. The wettability of the tooth surface as influenced by fluoride application, contact with fluoride containing materials (pit and fissure sealants) and certain dental procedures such as etching and polishing are being studied. The wettability of fluoride-free and fluoride-containing materials will be compared.